The present invention relates to vehicle-mounted signs and, more particularly, to electronic display systems for use with vehicles.
European patent application no. 0 131 211 titled "Programmable Electronic Vehicular Display System," by Karlstrom et al discloses a vehicular display and radio receiver combination that obtains and displays information from a central transmission processor. The received signals include messages, advertisements, pictures, etc., which are displayed upon the vehicle by means of a matrix display panel. The panel is mounted on the roof of the vehicle so that information can be readily perceived by persons in proximity to the vehicle.
One of the drawbacks of the aforementioned system, however, is its complexity and cost. The system requires RF transmission apparatus and complex circuitry. Moreover, this display system does not permit information to be constantly displayed. That is, the message displayed is either flashed or rolled across a screen in billboard fashion.
Another drawback of the aforesaid system is that a number of vehicular displays are controlled from a central source. Should the central transmission fail, or become interrupted, all the vehicles in the fleet would be unable to display any information.
Accordingly, it would be advantageous to provide a system which is not dependent on a central source for its information, nor one that is controlled by radio frequency transmissions.
It would also be advantageous to provide a system that would allow both animated and unanimated information to be simultaneously displayed from a vehicular screen.
It would be a further advantage to have a vehicular system for displaying information that can be controlled from within the vehicle. Vehicle-controlled information is far more useful to the operator, since the driver of the vehicle can display messages of a robbery or hijack in progress, or messages requesting police or medical assistance. Such personalized information is not available from centralized transmissions. In the case of a robbery or hijack, such displayed information acts as a quiet alarm. The perpetrator of the crime is not aware that the vehicle operator is signalling for help. In the case of a medical emergency, such as when a passenger is having a cardiac arrest, the driver does not have to stop to call for assistance. A lighted or blinking message sign would also provide a more meaningful way of informing by-standers of a speeding emergency vehicle in city traffic.
Another advantage of such a display system, would be provided by a means for quickly mounting the display mechanism upon the roof of a vehicle. A quickly assembled sign would be useful for purposes of repair or replacement.